This paper describes the development and validation of an advanced boiler simulation tool for Units 1 and 2 at the Youngheung Power Plant in South Korea. By combining 3-D computational fluid dynamics (CFD) analysis of the furnace with a 1-D steam-water side model it is possible, for example, to simulate the effects of burner and SOFA settings, firing patterns and coal blending on the boiler efficiency and pollutant formation, as well as the combustion efficiency. The models are coupled by exchanging temperature and heat flux values on furnace walls and heat exchangers at each iteration of the calculation to ensure that the final converged solution is a self-consistent solution for the combined furnace, boiler and turbine system. The ANSYS CFX software was used to develop the CFD model, while the 1-D boiler model was created in the PROATES Off-Line software of E. ON Engineering. The model has been validated for a typical operating condition by comparing the simulated results with the plant data. Good agreement is obtained, confirming that the coupled model has the capability to contribute significantly to the comprehensive optimisation of the boiler operation as well as acting as a problem solving tool. It is expected that the same coupling strategy can be adapted for any type of pulverised coal-fired boiler. (C) 2010 Elsevier Ltd. All rights reserved.